1. Field of the Invention
The present invention generally relates to generation of visual effects by combining a first pattern with a second pattern, and more particularly to combining patterns where the second pattern is an enantiomorph (or “mirror image”) of the first pattern, with the combined first and second patterns producing an intelligible image only when in specific positions relative to each other.
2. Description of the Prior Art
Traditionally, several toys, advertising devices and other devices create variable patterns that can be beautiful and eye-catching because they have bilateral symmetry (as does a butterfly) or rotational symmetry (in which the same pattern appears more than once around a circle) or symmetry of both kinds together. The kaleidoscope invented by David Brewster is an example: fragments of colored glass, for instance, are reflected by mirrors so that they generate visible patterns, which vary although they always remain symmetrical (both bilaterally and rotationally). Other devices provide visible elements that can be brought together to form intelligible designs, for example when concentric discs become properly aligned. There are various patents in the same general area as the invention.
U.S. Pat. No. 3,122,859 (La Reaux) discloses a viewing-tube toy, in which a range of elements can be added to an intelligible design. For instance, a man can be given a choice of hats, or can appear with or without a beard. The various elements are arranged on concentric sheets, which can be rotated independently, the varying visible combinations then filling a sector of a circle that is viewed through the tube.
U.S. Pat. No. 3,099,933 (Weiner) discloses a viewing-tube toy, in which a pattern is rotated, only half the pattern being visible at any stage. The visible half is reflected in a mirror, so that a bilaterally symmetrical arrangement is seen in the tube. Several successive intelligible shapes can be encoded into the pattern. If, for instance, the left half of a butterfly is shown in part of the pattern, then at one stage in the rotational cycle the entire butterfly will be seen.
U.S. Pat. No. 6,009,647 (Feingold) discloses the scrambling and unscrambling of a message which is distributed between at least three concentrically arranged discs. The discs are independently rotatable, the message appearing when they are properly aligned.
U.S. Pat. No. 6,300,983 (Fels et al.) discloses patterns coming from a television camera and subsequently processed electronically so that the patterns are seen distributed around a circle, half the time rotated and half the time mirror-imaged as well as rotated, so that rotational and bilateral symmetry is generated. A televised man, for instance, could be seen as facing himself in several sectors of the circle.
U.S. Pat. No. 1,796,903 (Wheeler et al.) discloses concentric drums, an intelligible design being rotated inside a copy of the design that is exact rather than mirror-imaged. The design will therefore be seen when the drums become properly aligned.
Devices such as these reflect a widespread interest in variable patterns, symmetrical patterns and encoded patterns that can become decoded. However, prior inventors have produced comparatively uninteresting and unattractive visual effects because they have failed to take advantage of the fact that when a first pattern is appropriately combined with a second which is its enantiomorph and which is rotatable relative to it, bilateral and optionally also rotational symmetry will be present in all stages in the rotational cycle, and one can encode an intelligible design of absolutely any desired complexity into the first pattern so that it appears unexpectedly at one or more stages in the cycle.